Combined knife and shears grinder.



S. M. HERSHEY.

COMBINED KNIFE AND SHEARS GRINDER. APPLICATION FILED OOT.4, 1912; RENEWED MAR. 23, 1914.

1,097,22 Patented May19,19'14.

messes Q Q 52233;)?

' zkdliy UNITED STATES PATENT OFFICE.

SAMUEL M. HERSHEY, 0F NEWARK, NEW JERSEY.

COMBINED KNIFE AND SHEARS GRINDER.

Specification of Letters Patent.

Patented May 19, 1914..

Application filed October 4, 1912, Serial No. 723,860. Renewed March 23, 1914. Serial No. 826,748.

- New Jersey, have invented a new and useful Improvementin Combined Knife and Shears Grinders, of which the following is a specification. I

Among the objects of my invent-ion are the production of an improved grinder of cheap and simple construction and which is particularly adaptedfor the effective grinding both of instruments having a single cutting edge such as a carving knife or the like, and also the grinding of instruments which operate by the co-action of two cutting edges, such as shears or the like, and

which are ground at a very much greater cutting angle.

ith the foregoing and related objects in view, my invention consists in the parts, improvements and combinations hereinafter set forth and claimed.

While I have shown and shall describe my invention as embodied in one specific form, it is to be understood that the invention is not restricted thereto but is-as broad as my claims.

In the drawings forming part of this specification, and wherein the same reference numerals are applied to the same parts throughout, Figure 1 is a side elevational view of a form of grinding device embodying my invention. and Fig. 2is a similar view at right angles to Fig. 1, part thereof being in cross-section on the line 22, Fig. 1.

Reference numeral 1 is applied to the frame which afiords a bearing for the grinding wheel and at the same time provides a means of conveniently attaching the same to a support, and preferably and as shown in the drawings, this member consists of a casting which is provided with projecting lugs 2, which are designed to be placed on the top of a horizontal surface such as, for example, a table, and separated therefrom at a convenient distance, is a lug 3 extending parallel to the lugs 2,2 and having a hole 4 tapped therein. The thumb screw 5 is screwed within the threaded opening 4 and serves with the lugs 2 to conveniently secure the device to a support as will be readily understood. The member 1 is preferably extended at its upper end in a direction parallel to the lugs 2 and 3 as shown at 6, and a cylindrical opening 7 is formed therein, the extension 6 with the opening 7 constituting a bearing for the grinding device.

The grinding wheel 8 which is preferably of alundum, carborundum, emery or the like has a central. opening 9 and is provided with a recess 10 on its upper face concentric with the central opening 9. A guide member 11, which is preferably an iron casting, is provided with a central opening 12, and comprises a convex surface 13 which extends for a distance within the recess 10 in the grinding wheel 8 and terminates in a shoulder 14 which rests firmly against the face of the grinding wheel. The outer portion 15 of the guide member 11 forms a portion of the outer surface of the cone, the elements of the cone making an angle of 30 degrees or thereabou't with the axis of the shaft 16. The shaft 16, enlarged between its ends at 17, extends through the opening '9 in the grinding wheel 8 and the opening 12 in the guide member 11 and is provided with a .nut or other fastening means 18 firmly holding the grinding wheel and guide member 11 in place against the enlargement 17 of the shaft. The opposite end 19 of the shaft is passed through the opening 7 in the member 6 and is provided at its end with a retaining means such as the nut 20.

The grinder is first clamped to any suitable supporting means such as a table, leaving the upper surface of the wheel 8, preferably in a substantially horizontal position.

Of course, as will be understood, the device may be used in different positions according to the requirements of the user. With the device firmly secured in place, in order to sharpen an instrument with a single cutting edge such as a carving knife, the instrument is placed between the guide member 11 and the grinding wheel 8 and is pressed inwardly toward the center of the grinding wheel and at the same time against the lower convex face 13 of the guide member 11 so as to secure the correct cutting angle. It is thenv moved lengthwise between the guide and the grinding wheel and the lengthwise movement operates to rotate the grinding device and to mcure an efiicient grinding action. By passing the knife through the grinding device a half dozen times or so, a. sharp-cutting edge can readily be secured.

For grinding instruments such as shears, which require a very much larger cutting angle, the blade to be ground. as for instance, one of the blades of a pair of shears,

is passed repeatedly through the grinding device in the same manner as the carving knife already described, except that instead of being pressed against the lower face 13 of the guide member 11 and being guided in contact with the grinding wheel thereby, it is pressed against the outer face 15 of the guide member 11 thereby securing the proper angle of the cutting edge. As I have shown in the drawings this guide face forms substantially an angle of 30 degrees with the central axis so that the cutting edge ground thereby would have substantially an angle of 70 degrees. This angle, of course, can be varied Without departing from my invention.

Having now described my invention, I claim:

1. In combination, a rotatable grinding wheel provided with a recess in its surface, a guide member having a convex guiding surface extending within the recess and terminating in a shoulder at the bottom of the recess and-firmly secured to said grinding wheel so as to rotate therewith, substantially as set forth.

2. In combination, a rotatable grinding wheel provided with a recess in its surface, a guide member having a convex guiding surface extending within the recess and terminating in a shoulder at the bottom of the recess and provided with a second guiding surface at a different and distinct angle and firmly secured to said grinding wheel as to rotate therewith, substantially as set forth.

In testimony whereof I have signed my name hereto in the presence of two subscribing witnesses this 3rd day of October, 1912.

SAMUEL M. HERSHEY.

Witnesses H. H. DYKE, LILLIAN M. FUNKE. 

